Rachmat Triandi Tjahjanto

Effect of Tin Electrode (Sn), Electrode Distance and Thin Layer Size of Zinc Phthalocyanine (ZnPc) to Resistance Changes With Ozone Exposure

This study was aimed to determine the effect of tin electrode distances and the thickness of a thin layer of ZnPc (Zinc phtyalocyanine) toward changes in resistance with ozone exposure. Tin deposition on the glass surface was conducted using spraying method. The reaction between ozone and ZnPc produces electrical properties that can be read through the resistance value of the multimeter. Based on this study, it was investigated that the smaller a distance between the electrode and the thicker deposition of ZnPc lead to the less resistance. This showed that a thin layer of the conductivity increases along with the longer exposure to ozone gas. The movement of electrons with the hole was free.

Microstructure and crystallization of chemically derived PZT thin film using controlled solvent composition and rotational speed

Growth of thin film lead zirconate titanate (PZT) can be controlled via solvent composition and rotational speed. The objective of this research is to build a crack-free microstructure of PZT films and high crystallinity by modifying sols concentration in the sol-gel process and rotational speed in the spin coating process. The synthesis of PZT sols with the composition ratio of Pb/Zr/Ti: 100/50/50 near morphotropic phase boundary (MPB) was prepared with various sol concentrations by propanol addition of 1, 3, and 5 ml. The sols were deposited using spin coating technique onto silicon wafer substrate with rotational speeds of 2000 rpm, 3000 rpm and 4000 rpm, respectively. The microstructure of PZT films were characterized using XRD and SEM instruments. The XRD results show the intensities of the certain crystal orientation which indicate that the crystal size decreases with the increasing solvent composition and rotational speed. On the other hand, SEM images indicate that the increase in the rotational speed and less solvent addition provide the PZT films with better morphology including its fineness, flatness and homogenity. Furthermore, it was found that the number of cracks on the surface of PZT thin film could be minimized and even eliminated by adding small amount of solvent and increasing rotational speed. The percentage of tetragonal and rhombohedral phase is in the range of 33 % and 67 % respectively, indicating the chemical composition of PZT lies near MPB.

Study of Ozone Synthesis With Methods of Plasma Discharge

In this research an ozonator prototype has been built to produce ozone, consists of air pump, gas flowmeter, an ozone reactor, and a glass pipe of nozzle. The most important part of the device is the reactor which consisting three main parts; 5 mm alloy electrode connected to a high voltage generator in the form of electrical gas stove lighter, 1 mm copper negative electrodes connected to the ground and a glass plasma discarge. The ozone gas formed is flowed to a container consisting of methyl orange solution 20 ppm at wave lenght of 470 nm. The concentration of ozone is determined by spectrophotometry method. The ozonator is characterized by ozonation periode variation of 5, 10, 15, 20, 25, and 30 minutes with the voltage used 3,5 volt, voltage variation of 3, 4, and 5 volts and flow rate variation of 227, 363, 464, 662, 864, and 1060 mL/min at the voltage used 3.5 volt. The result showed that the longer period and the higher voltage used for ozonation, the higher the ozone gas produced. The concentration of ozone obtained in this research is 0.76 ppm reached at 363 mL/min with 20 minutes ozonation duration.